Pipe-turning mandrels



United States Patent C PIPE-TURNING MANDRELS.

Harold W. Wheeler, Harrison Township, Kandiyohi County, Minn.

Application August 16, 1956, Serial. No. 604,505.

2 Claims. (Cl; 279-2) My invention relates to improvements in pipe-turning mandrels for unscrewing orscrewing-lengths of pipefrom or into pipe fittings.

It frequently happens that a pipe becomes broken oif at or near a fitting into which it has been screwed'l'eaving the threaded end of the pipe in the fitting insufliciently exposed for the application of an ordinary wrench thereto exteriorly thereof for unscrewing the same fromthe fitting. It is also frequently desirable to screw into a pipe fitting a nipple which is too short to receive a wrench exteriorly thereof without dangerof injury to the threads at the outer end of the nipple.

An object of my invention is to provide an improved pipe-turning mandrel, generally of the nature of an inside chuck, adapted to be turned with an ordinary wrench for the internal gripping of lengths of pipe, for example as aforesaid, to enable the user quickly and easily to unscrew or screw such a pipe from or into a pipe fitting, a further object being to provide such a tool which is markedly simple, durable, compact, efficient, relatively light in weight and relatively inexpensive.

More particularly, it is an object of my invention to provide a pipe-turning mandrel employing expansible jaw members connected to the body formed. as a nut to receive a wrench for turning the tool, and employing a jaw expander which coacts only with the jaw members, entirely independently of the body and of the connections between the body andv jaw members.

Other objects of the invention reside,v inthe novel combination and arrangement of parts and in the details of construction hereinafter illustrated and/ or described.

In the drawings:

Fig. 1 is a perspective view of a pipe-turning mandrel constructed in accordance with my invention.

Fig. 2 is mainly a central longitudinal-sectional view of the structure shown in Fig. 1, a portion of the expander nut being shown in elevation.

Fig. 3, like Fig. 2, is also a central longitudinal-sectional view of the structure shown in Fig. 1, said Fig. 3, however, showing the tool axially turned through ninety degrees as compared with Fig. 2.

Reference being had to the drawing, it will be seen that the illustrated embodiment of my invention includes a body A, similar jaws members B connected to the body, and a jaw expander C.

The body A is shouldered in the form of a nut and has at its forward end an annular guard flange 10. Said body A is formed with an axial bore 11 therein and with elongated apertures or slots 12 which extend axially of the body A and open radially into said bore 11 in said body, there being one such aperture or slot 12 for each jaw member B.

In the illustrated structure, two jaws members B are shown, although, as will be readily comprehended, three or more such jaw members may be employed. Preferably, each jaw member B has longitudinally straight outer and inner faces 13, 14, the outer face 13 being laterally hereinafter appear. Fixedly secured to the butt portion.

15 of each jaw member Bis a pin 18which extends radially outward from such jaw member and is received inv the elongated aperture or slot 12 provided in the body A for such member B, the thickness of the pin 18 being slightly less than the width, of the slot 12, enabling said pin to. tilt in said slot and accommodate outward and inward swinging movements of the jaw member B away from and back toward the axis of the body A, while at the same time depriving the jaw member B of movement relative to the body A about the axis of said body.

The jaw expander C includes a stem 19 which is received in the said space 17 between, the jaw members 33. At the forward end of this stem 19 is a conically tapered head 20 adapted wedgedly to coact, with the main portions 16 of the jaw members B interiorly thereof at their tips. The rear portion. of the stem B isformed withthreads 21 and extends rearwardly from. the. butt ends 151 of the jaw members, B which ends of said members are preferably rounded, as at 22. Threaded on the stem 19 is an expander nut 0 including an intermediate shouldered portion 23, for application thereto of a wrench. This expander-nut c has an annular combined bearing and guard flange 2.4 forwardly of its shouldered intermediate portion 23 and, rearwardly of said intermediate portion 23, the, said expander nut c hasv a finger piece 25 formed with-wing portions 26..

By unscrewing: the expander not 0 on the stem 19, said stem may be. moved forwardly between the jaw members B to shiftv the tapered head 20 forwardly into position clear of the tips of said jaw members B, or forwardly at least enough to enable the jaw members B to be swung together into sufliciently narrow compass to enter a pipe to beturned by the tool, it being understood, of course, that such pipe would be within a range of, sizes to which any particular tool would be adapted. After inserting the main portions 16 of the jaw members B into a pipe, the expander nut 0 will be preliminarily tightened through the medium of the finger piece 25 bringing the flange 2d of the expander nut 0 against the butt ends 15 of the jaw members 13 and causing the tapered head 26 of the jaw expander C to coact with said jaw members B swinging them apart and into contact with the inner surface of the pipe. To cause the jaw members B to grip the pipe with relatively great force, an ordinary wrench will be applied to the shouldered intermediate portion 23 of the expander nut 42 for the further tightening of said nut. This further tightening of said expander nut. c forces the bearing flange 24 of said nut against the rounded butt ends 15 of the jaw members B and, in opposition thereto, forcibly draws the tapered jaw-spreading head 20 on the stem 19 between the main portions 16 of the jaw members B at the tips thereof, the force exerted by the jaw expander C being directed solely against the jaw members B, entirely apart from the body A and the connections between said body and the jaw members 8. In addition to engaging the butt ends 15 of the jaw members B, the flange 24 on the expander nut c guards said ends of said jaw members against a wrench applied to said expander nut in turning the same. Said flange 24 also guards such wrench against said butt ends 15 of 1 said jaw member B.

Patented Nov. 24, 1959 against the interior surface of a pipe, the body A will be turned in one direction or the other, as may be desired, by means of an ordinary wrench applied to said body, the turning of the body being imparted to the jaw members B through the pins 18 which connect said jaw members to said body A. The annular fiange at the forward end of the shouldered body A guards the work to which the device is applied against a wrench fitted to said body and guards such wrench against such work.

To free the tool from a pipe to which it has been applied, the expander nut c is preliminarily loosened on the stem 19 by means of a wrench fitted to the shouldered portion 23 of said nut, said nut being thereupon further loosened through the medium of the finger piece 25 to release the grip of the jaw members B on the pipe.

Preferably, each of the jaw members B will have a set of grooves 27 exteriorly thereof which extend longitudinally of the main portions 16 of said jaw members, and will have a second set of grooves 28 laterally of said main portions of said jaw members. On each jaw member B, said grooves 27, 28 provide laterally extending rows of shoulders 29. The shoulders 29 in each row 'thereof alternately face in opposite directions laterally of the jaw member and they bite into a pipe to which the tool is applied, enhancing the grip of the jaw members B on such It will be readily appreciated that all of the various stated objectives of my invention are fully met in a structure constructed in accordance with the invention.

Changes in the specific form of the invention, as herein described, may be made within the scope of what is claimed without departing from the spirit of the invention.

Having described the invention, what is claimed as new and desired to be protected by Letters Patent is:

1. A pipe-turning mandrel comprising a body in the form of a nut adapted to be turned by a wrench, said body having an axial bore therein, elongated jaw members arranged side by side about the axis of said body, said jaw members having main portions extending forwardly from the body and having butt portions extending through said bore in said body and rearwardly therebeyond, a jaw expander including a stem and a tapered head on said stem, said head being interposed between said main portions of the jaw members at their forward ends, said stem extending axially of the body rearwardly from said tapered head between and to the rear of said jaw members, the rear portion of said stem being threaded, the butt portions of the jaw members being loosely accommodated in said bore in said body between said body and expander stem, individual connecting means for each jaw member, such means in each instance connecting its respective jaw member to the body for swinging movement away from and back toward the axis of said body, while depriving its jaw member of rotational movement about said axis independently of said body, the several individual connecting means between the jaw members and body transmitting rotational force from the body to the jaw members within the end-to-end confines of the body, the tapered head of the jaw expander being adapted upon rearward movement thereof relative to the jaw members to engage the main portions of said jaw members wedgedly and swing them apart expanding the same, an expander nut fitted on the threaded portion of said stern, said expander nut being screwable on said stem against the ends of the butt portions of the jaw members bringing the tapered head of the jaw expander into jaw-expanding engagement with said main portions of said jaw members, the opposing forces exerted by the head of the jaw expander and expander nut in expanding the jaw members being directly applied to the jaw members themselves independentlyof and apart from the several connecting means between said jaw members and the body of the mandrel.

2. A pipe-turning mandrel, as defined in claim 1, wherein the body is formed with apertures therein elongated axially of the body and opening radially into the bore thereof, there being one aperture for each jaw member, and wherein the individual means connecting each jaw member to the body includes a pin extending radially outward from its respective jaw member and received at its outer end in its respective aperture in said body for tilting movement therein longitudinally thereof.

References Cited in the file of this patent UNITED STATES PATENTS 1,231,262 Katchmazenski May 15, 1916 1,813,567 Delorme July 7, 1931 1,892,904 Robinson et al J an. 3, 1933 2,320,435 Hood June 1, 1943 2,497,633 Shapiro et a1 Feb. 14, 1950 FOREIGN PATENTS 205,291 Germany Apr. 11, 1908 

